Battery terminals for automobile, industrial and other uses are typically connected using either posts which extend from the top of the battery casing or threaded connections in the sides of the battery casing. Connections to threaded terminals are generally made using a lug and a bolt that is threaded into the battery terminal and tightened with a wrench. The battery terminal is molded into the side wall of the battery casing and includes a bushing and a threaded insert inside the bushing, which receives the bolt.
A common problem encountered with threaded battery terminals is that over-torquing an overlong bolt forces the bolt through the bottom wall (also referred to as the back wall) of the insert and can either damage the weld zone that connects the terminal to the battery plates or rupture the battery casing and make the battery unusable. A variety of different terminal designs have addressed this problem but none of them have been completely successful.
One of the problems encountered in designing a battery terminal insert that can withstand over-torquing and overlong bolts is the limited amount of space in the battery casing. Industrial batteries are typically mounted in racks or cabinets that are constructed for standard size batteries. Any replacement battery has to have the same “footprint” as a standard size battery in order to be an acceptable replacement. If the footprint of the battery is increased to accommodate a larger battery terminal insert, the footprint of the battery will be too big to fit in standard racks and cabinets. If the battery casing is reduced in size to allow room for a larger battery terminal insert, the battery cells will be smaller and the battery will have less power. Therefore, two of the considerations in designing a battery terminal insert are that the insert cannot change the size of the battery footprint and that the insert must not extend too far into the battery casing. Accordingly, there is a need for a battery terminal insert that extends a minimal distance into the battery casing and can provide a proper connection using a minimum number of threads. There is also a need for a battery terminal insert that can withstand over-torquing and overlong bolts without permanently damaging the battery.